Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• known solution-based synthetic procedures more environmentally friendly by avoiding the solvent which is also one of the major drawbacks. So development of innovative bond formation reactions under mechanomilling should be highly appreciated that are inaccessible from solution phase chemistry

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• Warner have proposed 12 Principles of Green Chemistry as a guide to help making chemical processes more environmentally friendly [13][14]. Many of the requirements contained in these principles (e.g., prevention, atom economy, energy efficiency, catalysis, safe synthesis) can be met if the reactions are

• reactions in an environmentally-friendly fashion [17][18]. In this respect, there have been several turning points in the development of solid-state mechanochemistry. The first key discovery was made by Jones et al. who discovered the rate-accelerating effect of adding small catalytic quantities of a liquid

• corresponding saccharyl ureas 44a–d were isolated in high yields after CuCl-catalyzed (10 mol %) LAG for 2 hours (Scheme 19). These several examples of sulfonylureas nicely demonstrate that ball milling is also a very powerful environmentally-friendly synthetic tool in medicinal chemistry. Mechanochemical

Mechanochemical N-alkylation of imides

• Anamarija Briš,
• Mateja Đud and
• Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

• synthesis of amines by their reaction with 1,2-diaminoethane. Keywords: ball milling; Gabriel reaction; imides; mechanochemistry; N-alkylation; Introduction The development of environmentally friendly organic reactions is a growing area of interest [1]. The reduction of the impact of chemical reactions on

• a precedence in the application of weaker base in mechanochemical synthesis of triphenylphosphoranes [32]. Often DMF is used as solvent in imide alkylation reactions, which promotes SN2 reactions [33] and its low volatility is advantageous over more environmentally friendly solvents which might be

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• an economic and environmental standpoint, it is highly desirable to develop more environmentally friendly synthetic methodologies. Several studies were dedicated to the design of a novel catalytic system, that are more accessible, robust, efficient and ligand-free [19]. In that sense, nanoparticles

• Wittig reaction followed by different metal-catalyzed reactions and harsh conditions are usually required [60][61][62]. In our case, the desired product was obtained under environmentally friendly reaction conditions and in a short reaction time. Thus, the PVP-Pd NPs proved to be an effective catalyst to

• modified, and probably this structure is responsible for the activity since it leaves enough surface available to perform the catalytic reaction. Conclusion In summary, the PVP-Pd NPs exhibit an outstanding catalytic activity in the Mizoroki–Heck reaction under environmentally friendly reaction conditions

Sustainable synthesis of 3-substituted phthalides via a catalytic one-pot cascade strategy from 2-formylbenzoic acid with β-keto acids in glycerol

• Lina Jia and
• Fuzhong Han

Beilstein J. Org. Chem. 2017, 13, 1425–1429, doi:10.3762/bjoc.13.139

• , as an environmentally friendly reaction medium, has received increasing interest for organic reactions because of its peculiar physical and chemical properties such as polarity, low toxicity, biodegradability, high boiling point, and ready availability from renewable feed stocks [31]. Many organic

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• dethreading already takes place. This multistep reaction methodology hinders the large-scale production and broad application of these materials. Recently our group has developed a method for a simple and environmentally friendly synthesis of polyrotaxanes. This, so called rotaxa-polymerization, is an aqueous

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

Chemoselective synthesis of diaryl disulfides via a visible light-mediated coupling of arenediazonium tetrafluoroborates and CS₂

• Jing Leng,
• Shi-Meng Wang and
• Hua-Li Qin

Beilstein J. Org. Chem. 2017, 13, 903–909, doi:10.3762/bjoc.13.91

• visible light-promoted coupling of readily accessible arenediazonium tetrafluoroborates and CS2. This practical and convenient protocol provides a direct pathway for the assembly of a series of disulfides in an environmentally friendly manner with good to excellent yields. Keywords: arenediazonium

• has also been studied [14][15] by taking advantage of visible light as abundant and environmentally friendly energy source for organic syntheses. The photochemistry of diazonium salts has been widely studied since the early 19th century, at which time, it was noticed that benzenediazonium nitrate

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

• Katarina Kemper,
• Max Hirte,
• Markus Reinbold,
• Monika Fuchs and
• Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

• inaccessible. A good example is the mutagenesis of the bacterial diterpene synthase CotB2 that resulted in dolabellatriene-type scaffolds, which were by then mostly found in marine organisms [59]. To that end, these new routes can provide substantial and environmentally friendly alternatives for sourcing

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• uptake and use of an excess of amine (quinoline) modifier [12][13], with serious drawbacks in terms of process economy, environmental impact and product separation management. The development of cost-effective, well-defined, efficient and environmentally friendly catalytic systems for the partial

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• -deficient aryl bromides provided good to excellent yields. D-Glucose represents a type of environmentally friendly ligand and can be easily removed during the work-up process. This work is of special value as it was the first report employing copper(II) as the catalyst in the synthesis of phenols. In 2011

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

• Flavio Fanelli,
• Giovanna Parisi,
• Leonardo Degennaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

• , the catalyst can be fixed on a suitable hardware, and the reaction mixture allowed to flow through the system. The use of recyclable catalysts in continuous-flow conditions represents an innovative strategy for the development of more environmentally friendly synthesis. In the last decade, organic

Catalytic Wittig and aza-Wittig reactions

• Zhiqi Lao and
• Patrick H. Toy

Beilstein J. Org. Chem. 2016, 12, 2577–2587, doi:10.3762/bjoc.12.253

• reaction mixture in order to make the reactions more environmentally friendly. As was the case in the previous work described above, both aromatic and aliphatic aldehydes 6 were suitable substrates in this reaction system to form products 7. Most recently the Tang research group has reported the use of

• methods for phosphine oxide reduction are discovered [42][43][44][45][46][47], catalytic reactions involving cycling between phosphines and phosphine oxides will become more environmentally friendly and more popular too. With regards to the phosphine oxide-catalyzed aza-Wittig reactions discussed, while

A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

• Donghui Pan,
• Yanbin Wang and
• Guomin Xiao

Beilstein J. Org. Chem. 2016, 12, 2443–2449, doi:10.3762/bjoc.12.237

• in the bromination process [10][11][12]. In addition, the release of corrosive HBr as a byproduct and the use of organic solvents make this protocol less environmentally friendly [13]. The use of other brominating agents, such as N-bromosuccinimide (NBS) and pyridinium tribromides, also has the

Selective and eco-friendly procedures for the synthesis of benzimidazole derivatives. The role of the Er(OTf)₃ catalyst in the reaction selectivity

• Natividad Herrera Cano,
• Jorge G. Uranga,
• Mónica Nardi,
• Antonio Procopio,
• Daniel A. Wunderlin and
• Ana N. Santiago

Beilstein J. Org. Chem. 2016, 12, 2410–2419, doi:10.3762/bjoc.12.235

• organic solvents and lack of selectivity [15][16][17][18][19][20][21]. Rare earth metals are economical and readily available from commercial sources and represent useful catalysts in organic synthesis [22]. In particular, erbium(III) promotes environmentally friendly reactions [23][24][25], and has been

• environmentally friendly synthetic method, to obtain different derivatives containing the benzimidazole core by a one-pot reaction. Additionally, Er(OTf)3 was selected as the catalyst to achieve the selective formation of products in order to avoid tedious work-up and product separation procedures. Moreover

• solvents, which are not environmentally friendly. Thereby, we propose the use of Er(OTf)3 as catalyst to provide an eco-friendly, economical and easy to work-up procedure for the synthesis of 1,2-disubstituted benzimidazoles, which can be afforded in only two minutes. In order to selectively obtain 2

β-Amino functionalization of cinnamic Weinreb amides in ionic liquid

• Yi-Ning Wang,
• Guo-Xiang Sun and
• Gang Qi

Beilstein J. Org. Chem. 2016, 12, 2372–2377, doi:10.3762/bjoc.12.231

• -protecting groups is relatively easier than those shown above; and 3) the ionic liquids are environmentally friendly and can be readily recycled. Results and Discussion The first attempt was to conduct the aminochlorination reaction of N-methoxy-N-methylcinnamoylamide (5a) in acetonitrile by using 2-NsNCl2

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• -chloro-CDs [15] in solution. The solubility of per-6-halogeno-CDs is very limited in water and the majority of organic solvents, meaning that their preparation and purification is far from being environmentally friendly. Per-6-S-(3-mercapto)propionyl-γ-CD (Sugammadex, Bridion®) is not only the biggest

• drug targeting hosts [7][8], can be problematic as they require sophisticated, efficient and yet simple methods which lead to acceptable purity and impurity profiles. Furthermore, the special structural properties of selectively substituted CDs mean that their syntheses are not always environmentally

• friendly procedures. Ball mill assisted syntheses are good alternatives to overcome solubility difficulties in syntheses or isolation of natural compounds from vegetables using CDs [9][10]. Environmentally benign synthetic methods of CD derivatives have been recently reviewed [11]. The key intermediate in

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• avoided, making the process more environmentally friendly and sustainable. Furthermore, quantitative yields can be achieved, avoiding work-up and laborious purification [2]. Moreover, solubility problems, like insolubility of one reactant or the different polarity of two reactants, are solved. Examples

Solvent-free synthesis of novel para-menthane-3,8-diol ester derivatives from citronellal using a polymer-supported scandium triflate catalyst

• Lubabalo Mafu,
• Ben Zeelie and
• Paul Watts

Beilstein J. Org. Chem. 2016, 12, 2046–2054, doi:10.3762/bjoc.12.193

• environmentally friendly method for the synthesis of para-menthane-3,8-diol from natural citronellal oil in 96% yield, under solvent free aqueous conditions. The acylation of para-menthane-3,8-diol with various acid anhydrides over polymer-supported scandium triflate (PS-Sc(OTf)3) catalyst was subsequently

• sustainability perspective, but clearly it is necessary to develop protocols that are as environmentally friendly and sustainable as possible. The terpene, citronellal (3,7-dimethyl-6-octenal, 1) is widely used as a feedstock material in the synthesis of fine chemicals such as menthol (2) and para-menthane-3,8

• variety of applications. The synthesis method involves the acylation of 3 with various acid anhydrides. The synthesis method also employs a polymer-supported scandium triflate as a water resistant and environmentally friendly acid catalyst. Results and Discussion Synthesis para-menthane-3,8-diol from

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• temperatures (170–200 °C). An acyclic organic carbonate that has recently received attention from the synthetic lubricant market is dipentyl carbonate (DPC). An environmentally friendly process for its synthesis has been recently proposed by the transesterification of DMC with 1-pentanol in the presence of 2

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• the Kröhnke-type synthetic methodology [23][24] starting from azulene carbaldehydes (1) [25] and 2-acetylpyridine (Scheme 1). In the first step, the 1-azulenyl-2′-azachalcone precursor 2 is formed via a Claisen–Schmidt aldol condensation. This reaction was performed in an environmentally friendly

TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals

• Mei-Yuan Hsu,
• Yi-Pei Liu,
• Sarah Lam,
• Su-Ching Lin and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2016, 12, 1758–1764, doi:10.3762/bjoc.12.164

• undergoes double SN2-like substitution by TPPO and the alcohol to give the α-glycoside as the major product [77] (Scheme 2, route B). Conclusion A simple, efficient, and environmentally friendly method for preparing S- and O-2-deoxyglycosides was established. S-2-Deoxyglycosides were obtained with moderate

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• hydrogen peroxide. Oxidizing systems containing hydrogen peroxide as the oxidizing agent allow the usual and asymmetric oxidation of the substrate to the target product with high conversion and yield. In recent years, the inexpensive, commercially available, and environmentally friendly H2O2 was utilized

Cp₂TiCl/D₂O/Mn, a formidable reagent for the deuteration of organic compounds

• Antonio Rosales and
• Ignacio Rodríguez-García

Beilstein J. Org. Chem. 2016, 12, 1585–1589, doi:10.3762/bjoc.12.154

• cyclization using reagents that are cheap, abundant and environmentally friendly. Certainly, this new methodology of deuteration will contribute to the synthesis of new deuterated organic compounds with applications as internal standards, pharmaceutical drugs and new materials, among others. Conclusion In

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• College, 771 Nakakuki, Oyama, Tochigi 323-0806, Japan 10.3762/bjoc.12.134 Abstract The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic–organic hybrid perovskite solar cells (PSCs) are very promising due